I hope to add more plans to this page, a new design every couple of months.
This kite was designed in the spring of 1993. The thing I was trying to accomplish with this design was a kite with dynamic washout (tip twist) that would twist off pull at the middle of the wind window but would have a wide window with good control at the edges. This dynamic twist makes the kite virtually impossible to pull out of the sky during a turn anywhere in the window. The tension in the trailing edge holds the winglets from twisting. As wind speed picks up the force on the winglets overcomes the tension of the trailing edge and twists back. This causes the tips to pick up relatively more aerodynamic load thus increasing drag and preventing tip stall. The kite can be adjusted for different wind ranges by adjusting the standoff length to ease or increase the tension in the trailing edge. More tension for more wind. This version has the trailing edge made up of straight line segments for ease of sewing. If you change to a continuous curve and install a leach line, somewhat better performance can be achieved. I have used 250-2 wrap graphite spars for a light wind version and AFC 2540 pultrude spars for a larger wind range version. I thought the heavier 2540 version flew better much to my surprise. Use standard construction techniques throught. The only exception may be the batten treatment. I connected the batten to the leading edge spar with a vinyl connector adjacent to the lower spreader connector. The batten is connected to the sail tip with a small elastic loop sewn along each edge and left open in the middle for the batten to go thru. For standoff length start with a length of 10 1/2 inches. This will undoubtedly be too long. Trim the length to tighten the sail without causing excessive bending in the lower spreader and spine. An inch or so of bending is ok. For heavier sparred units the standoffs can be longer without the resultant bending. Just use your own judgement.
jpg(60k) plan for the Tip Turn.
This is the highest aspect ratio delta stunt kite I have designed and built. It has a nose angle of 140 degrees. The leading edge spars are 65 inches long which is standard for an 8 foot wing span stunter, but the wing span on this kite is 10.6 feet. By using a large wing tip I was able to use the high aspect ratio, reduce washout and maintain a large sail area. If you want to surprise yourself draw a pointy wing tip on this design and calculate total wing area. It is appalingly less. Anyway as stated earlier for one of the other designs, the high aspect ratio and the limited washout of the tips greatly reduce vortex drag at low speeds. This kite is a very graceful low wind flyer that turns easily. I used Clearwater 0.202 2 wrap spars everywhere except for the lower spreaders. Their spans of 46 inches each dictated a stiffer spar, in this case a Clearwater 0.280 3 wrap spar. The sail is 1/2 oz Icarex. The three longest battens on each wing half are curved with the other two being straight. The battens can be made using 1/8 in diameter aluminum tube. Insert a fiberglass rod down the center and bend to the desired shape then pull the fiberglass rod out and you have a nice curved batten. The inboard standoffs are around 11 1/2 inches long and are attached to the sail at the trailing edge end of the first batten, or as close as construction techniques allow. There is also a set of outboard standoffs. These attach at the trailing edge of the third set of battens and to the lower spreader about 6 to 7 inches from the leading edge. Adjust them during test flight to get the best speed vs turning at the window edge. The farther the tips are pushed back the slower the kite will go and the smaller the window. These standoffs set the neutral point and help restrain some of the tip twist due to aero forces. The trailing edge contains a leach line to also help restrain the tips and to quiet the noise generated by trailing edge flutter. The original version had the leach line extending from the wing tips to the spine but I believe it will work better if it terminates at the third batten. To see a picture of The Higher Aspect Click Here.
Gif(12k) plan for The Higher Aspect.
All my kite designs presented on this web page are to be considered public domain.